


Biology Rendezvous

by sparksflycastiel (Seabrook73)



Category: Supernatural
Genre: Alternate Universe - College/University, Biology Lab Partners, Blow Jobs, Fluff and Smut, Hand Jobs, Intercrural Sex, M/M, Sexual Content
Language: English
Status: Completed
Published: 2015-12-10
Updated: 2015-12-10
Packaged: 2018-05-06 01:25:23
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,818
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5397662
Author URL: https://archiveofourown.org/users/Seabrook73/pseuds/sparksflycastiel
Summary: <blockquote class="userstuff">
              <p>Dean realizes there are certain advantages to being biology lab partners with his extremely smart (and extremely hot) boyfriend. During one particularly boring lab class, Dean decides to test Cas’ limits and makes him an arousing offer he can’t refuse.</p>
            </blockquote>





	Biology Rendezvous

**Author's Note:**

> Written for the [SPN Writing Challenge](http://spnwritingchallenge.tumblr.com/)
> 
> Find me on tumblr at [sparksflycastiel](http://sparksflycastiel.tumblr.com/)
> 
> Thanks to my always amazing beta, Lydia ([jensennjared](http://jensennjared.tumblr.com/))

“You are my favorite lab partner, Cas.”

“I am your only lab partner, Dean.”

“True,” Dean acquiesced, “doesn’t mean you’re not my favorite.”

Castiel rolled his eyes. “I’m honored. Now, would you like to stop playing footsie with me under the lab table so we can get back to finishing up this report?”

Dean screwed his face up in mock pain as Castiel stepped on his foot to keep it from creeping back up his pant leg. “Aw, Cas, you’re no fun.”

“I’m plenty of fun.” Castiel didn’t even look up from the notes he was studying. “You told me so yourself yesterday when we made out in the back of the campus movie theater.”

“Yeah,” Dean bit the end of his pen as a far off dreamy look washed over his face. “Good times.”

“Dean,” Cas scolded. “Focus please. We need to get this finished.”

“Hey, you’re the one who brought up the hot theater make out session.” Dean threw up his hands defensively. “You’re getting me hot and bothered all over again.”

“Point taken.” Castiel sighed. “Now come over here and explain to me your notes from lab last week. Your handwriting is atrocious. I can’t read any of it.”

“Hitting me where it hurts, huh Cas?” Dean stood up and moved around the table so he was able to read the notes over Cas’ shoulder. “Insulting my handwriting. What’s next, criticizing my highlighting skills?”

“Remind me why I put up with you again?”

“Because I’m adorable.” Dean leaned over Castiel, surrounding his lab partner with his arms as he ‘read’ the notes, mouth level with Castiel’s ear. “And because I suck you off during study sessions. It makes learning so much more fun.”

Castiel choked on air, nearly dropping the slide he was currently moving to view under the microscope. He whipped his head around to look at Dean. “Dean, I feel the need to remind you that we are not alone in this lab room right now.” Castiel growled.

“You’re so easy to rile up.” Dean smirked. “It’s almost no fun.”

Cas glared. “I am not easy to rile up. You just have no filter or sense of decency.”

“Oh, and you do?”

“Yes, of course.” Cas huffed.

Dean raised his eyebrow, accepting the challenge Castiel had unwittingly offered him. “Really?” Dean sank onto the lab stool next to Cas’. “So, if I did  _this_ ,” Dean smoothly moved his hand up Castiel’s thigh under the table, “and then maybe followed it up with this,” Dean brushed his fingers against Cas’ lap, “then that wouldn’t fluster you at all?”

Dean could actually hear Castiel gulp with the effort it took him to hold his poker face. “No.” He said tersely, hands white knuckling the microscope. “Not at all.”

“Huh.” Dean gripped Cas a bit harder under the table, lowering his voice so only Castiel could hear him. “Interesting. Because it seems to me that you’re sporting a semi in those holier than thou tax accountant slacks.” Dean palmed Castiel harder this time, causing Castiel to jerk his knee in response and loudly jostle the microscope, turning a few concerned stares briefly in his direction. “Hmm,” Dean hummed smugly as he brought both of his hands back up above the table. “Better be careful there, Cas. Wouldn’t want the rest of our peers to know just how not easy it is to rile you up.”

“You’re a jackass.” Cas hissed under his breath.

“A jackass that is about to give you options.” Dean gave Cas a look that was far too innocent given the game he was currently playing. “Option one, you can blue ball it through the rest of this three hour lab and then knock one out in the shower later.” Dean readjusted the microscope Castiel had knocked out of place as he nonchalantly offered up option two. “Or you can follow me into the supply closest and I’ll take care of you right now.”

Dean looked up to see Castiel staring at him, incredulous and wide eyed. “Choice is yours.” Dean shrugged. “Option two expires in two minutes. Starting now.”

Dean got up, leaving Cas flabbergasted as he headed across the hall to the biology lab supply room. The room was spacious, with several rows of shelves jam packed with various petri dishes and cardboard boxes full of long forgotten scientific journals. Dean wandered until he found a more secluded, although far from private, spot towards the back. He could see the light at the end of the aisle, indicating that the supply room door was still open to the hallway, undisturbed by any approaching figures.

Dean leaned against the supply shelf, waiting to see what Cas would do. He wouldn’t hold it against his partner if he decided to play it safe and refuse Dean’s risqué offer. After all, this was an honors college course, and it definitely was not in Castiel’s wheelhouse to risk his straight-A student image. In fact, the longer Castiel didn’t show up the more Dean worried he had already taken things a bit too far with the under the table hand play. Cas wasn’t really one for public indecency, even if it was pretty safe to assume no one had noticed what was going on.

Dean was about to head back into the lab room and admit defeat when he heard the supply room door shut with determination, the lock clicking into place as the light across the floor at the end of the aisle dimmed; only the light from the thin window in the door was getting through now. Dean’s heart rate skyrocketed into over drive as Cas rounded the corner of the aisle he was in, locking eyes with Dean. Dean almost let out a needy whimper at the look Cas was giving him. Fury mixed with heavy arousal, bright blue even in the dim light.

“This is not acceptable, Dean.” Cas’ voice was already an octave deeper than usual, making Dean’s dick twitch in his jeans.

“You’re gonna have to be a bit more specific, Cas.” Dean smirked as he sauntered forward. “I’ve done a lot of unacceptable things in my time.”

Dean’s words seemed to trip something in Cas, and the dark haired college senior surged forward, invading Dean’s personal space. By the time Dean realized he was no longer in control of this supply room tryst, it was too late. Castiel had him pushed up against the wall, his hips flush against his own, breath hot against his face.

“You are not allowed to work me up in front of a classroom full of our peers and my fucking  _thesis advisor_ and then give me ultimatums about getting off in the middle of class under threat of withholding sex if I refuse.” Cas glared.

“Aw, come on, Cas.” Dean licked his lips, knowing what it did to Cas. “No one likes a prude.”

“No one likes a  _tease_ , Dean.” Castiel emphasized his point by rolling his hips against Dean’s obvious erection.

Dean groaned as the pleasure spiked through him. “Who said anything about teasing?” He leveled Cas with a smoldering look as he snuck his hand between them and grabbed Cas through his pants. “For someone all high and mighty about this, you sure are turned on, Cas.”

Cas growled as he lunged forward, patience gone, and bit down on Dean’s bottom lip, sucking on it before he moved his mouth down Dean’s neck, latching onto his pulse point just below the neckline of Dean’s shirt. “Mmm,” Dean hummed his approval. “Gonna mark me up, Cas? Make sure everyone knows exactly who I belong to when we walk back into that classroom?”

“Shut up, Dean.” Cas muttered as he moved his hands to pop the button on his jeans. “I can think of several things your mouth could be doing other than talking right now.”

“Oh, baby, you are so into this.” Dean smirked as he pushed Cas’ hand aside, taking over for him as he worked Cas’ zipper down slowly, turning Cas around so he was the one pushed up against the wall.

The switch in positions seemed to jostle Cas out of his aroused stupor, suddenly reminding him where they were and what they were doing in a semi-public supply closet in their main academic building. Dean felt Cas tense up. “Oh no.” Dean locked Cas in against the wall. “No backing out now, hot stuff. You don’t get to give me a hickey the size of fucking Texas and then leave this rodeo. We’re gonna finish this thing.” Dean leaned in and kissed Cas deeply, distracting him as he worked his hands into his boxers.

“Dean,” Cas muttered against Dean’s lips, “are you sure,” Cas gasped as Dean’s mouth worked its way from his mouth to right below his ear, “no one,” Cas groaned as Dean’s tongue swept along the side of his neck, “is going to see us?” He finally managed to complete his thought, and good thing too because Dean once again crashed his lips against Castiel’s, stealing any breath – and shot at coherency – he had left.

“Yeah, Cas.” Dean smirked into Castiel’s mouth. “I’m sure. Pretty sure, anyway.” He pulled away slightly to look wickedly into Castiel’s eyes. “Why? You really gonna stop at this point?”

Dean accentuated his point by firmly and quickly stroking Cas, his cock finally free from his boxers. Cas threw his head back against the wall and moaned. Dean was right. The entire biology department could be hiding on the other side of the supply shelves and he wouldn’t give a rat’s ass as long as Dean kept doing what he was doing with his hand.

“Now,” Dean roughly twisted Cas in his hand again, thumbing at his slit, “word on the street is you like my mouth.” Without further ado, Dean dropped to his knees, and before Castiel could even process what was happening Dean took him into his mouth, swallowing around him.

“Holy  _fuck_ ,” Castiel swore, slamming his hands against the wall as he tried to find some purchase.

“Careful now, Cas.” Dean pulled off, tonguing at the head of Castiel’s cock in between his words. “Wouldn’t want that thesis advisor of yours to come see what the noise is all about.”

“You fucking fuck I am going to kill – oh  _god_.” Castiel’s threats died on his tongue as Dean swallowed him down again, hollowing his cheeks around Cas’ dick and humming a vibration he knew drove Castiel insane. It did the job, and soon Castiel had his fist in Dean’s hair, thrusting forward as his breath got more and more ragged, fucking into Dean’s mouth like they were in the privacy of one of their own dorm rooms and not across the hall from a classroom full of their colleagues.

“Dean.” Cas moaned. “Dean, Dean,  _Dean_  – I need –”

“What do you need, Cas?” Dean pulled off, but only for a moment, licking up the underside of Cas’ length before sucking sharply on its head. “Tell me what you need.”

“You.” Castiel gasped. “Please, Dean,  _please_.”

Dean needed no more urging, and this time when he swallowed Cas down he meant business. He set a relentless pace with his tongue, encouraging Cas to fuck his face by positioning his head at an angle that allowed Cas to thrust into his mouth easily, hitting near the back of his throat every time. It wasn’t long before Dean heard the tell tale hitch in Castiel’s breathing and felt the stutter of his hips that let him know Cas was on the brink. Seconds later Castiel was coming down Dean’s throat, Dean’s tongue happily helping him work through his orgasm as he swallowed Cas’ release. As Dean pulled himself off of Cas, he spun his boyfriend around so his front was leaning against the wall. He quickly pulled his achingly hard dick out of his jeans, spitting into his hand and slicking himself up to the best of his ability. Then he spread Cas’ legs enough for him to slip his cock between the apex of Cas’ thighs.

“Close ‘em tight, Cas.” Dean instructed as he playfully tapped Castiel’s hips, indicating that he should bring his legs together around Dean’s cock. As soon as Cas was in position, Dean started to push his cock along the curve of Cas’ ass and in between his thighs, his dick hitting against the back of Cas’ balls with each thrust. Given that he was pretty worked up from the killer blowjob he had just given Cas, it didn’t take long for Dean to reach his climax, spilling himself between Cas’ monstrously toned thighs.

Once he was sated, Dean leaned his forehead against the back of Castiel’s neck, breathing deeply as he tried to regain his composure. “Fuck, that felt good.” Dean muttered as he planted a kiss on Castiel’s shoulder blade. “You always feel good.”

“I still hate you.” Cas said unconvincingly, unable to keep the relaxed post orgasmic bliss out of his voice.

“Uh huh, you keep telling yourself that.” Dean chuckled as he finally pulled away from Cas, turning his lab partner around in his arms. “And just for hurting my feelings I am going to leave you here to clean yourself up, thank you very much.” Dean half-heartedly joked.

“Not a chance, Winchester.” Cas leaned across the way and plucked some paper towels off one of the supply shelves. “You’re the one who couldn’t control yourself and just had to come all over the back of my goddamn legs. Get to cleaning.”

Dean laughed again as he helped clean Cas up. “Don’t even try to tell me you didn’t love it.”

Castiel rolled his eyes, but there was a fond smile on his lips as he pulled his pants back up and buttoned his jeans. “You are a menace to society. And to our lab grade.”

“Ugh, lab.” Dean sighed as he tucked himself back into his jeans. “How long have we been in here?”

“Too long, lovebirds.”

Dean and Cas spun on their heels at the sound of a new voice in the supply room. “Charlie?” Dean’s hands flew to his hair, nervously trying to flatten what he knew was some serious sex hair thanks to the grip Castiel had had on his head when he was on his knees ten minutes ago. “Uh – what are you doing in here?” Dean stuttered unintelligibly.

“You mean what am I doing in the biology supply room in the middle of my senior biology lab class?” Charlie gave Dean her ‘I know you just had sex in here but really how stupid are you?’ look as she went to grab a box of microscope slides off the shelf. “Professor Singer asked for someone to grab some more slides. I quickly volunteered because I had a feeling there was a reason you two dumb asses were missing from class at the same time.”

“Oh, uh, thanks, Charlie.” Dean grabbed the back of his neck self-consciously. “We owe ya one.”

“Yeah, yeah, you can make it up to me by buying my drinks this Saturday when we go out to The Roadhouse.” Charlie rolled her eyes fondly. “Now may I suggest you two stagger your return to class? That’s how the pros do it.” She winked at them as she left the supply room.

“Well, that was mortifying.” Cas buried his face in his hands.

“Nah, come on, Cas.” Dean nudged Castiel’s shoulder playfully. “It was just Charlie. She’s seen us in worse states. Be thankful she didn’t come in a few seconds earlier. At least we were fully clothed by the time she walked in on us. Unlike that time at Sam’s 21st birthday party.”

“Don’t remind me.” Cas’ face twisted unpleasantly at the memory. “I couldn’t look Charlie in the eye for a week after that party.”

“I am sure it was just as scarring for her.” Dean laughed. “Alright, so you wanna go back in first or should I?”

“I’ll go.” Cas sighed. As he went to leave the room, Dean grabbed his hand and pulled him in for one last, soul-crushing kiss.  

“Thanks for making science fun, Cas.” Dean gave Cas his cocky half grin.

“You better watch yourself, Winchester, or you’re going to find yourself in need of a new lab partner.”

“I don’t know,” Dean laughed, “my current lab partner is the jealous type. Don’t think he’d like me making supply room runs with anyone else.”

“Hmm, you’re probably right.” Cas mused. “Guess you’ll just have to make up my lost lab time to me by typing up all of your chicken scratch notes by tomorrow.” Cas gave Dean a quick kiss on the cheek and retreated from the supply room before Dean could protest.

“That son of a bitch.” Dean laughed under his breath.

That would teach him to pair up with his overachiever boyfriend as a lab partner.


End file.
